The sealing and contacting of ultrasound flowmeters is a technically demanding and complex process. Housing openings have to be sealed using filigree seal elements made of the best sealing material. Due to the increased use of plastics materials, with which manufacturing tolerances cannot normally be ruled out, leaks may easily occur under specific operating conditions due to the small dimensions of the seal elements. Even if high-quality sealing material and time-consuming manual processing are selected, leaks still cannot be ruled out.
In recent years, the tendency has been to position ultrasound transducers in a housing so that the ultrasound burst produced by the ultrasound transducer enters the medium through a thin housing wall, generally consisting of plastic.